Add colour_t struct

include/colour.h

@@ -0,0 +1,14 @@
+#ifndef COLOUR_H
+#define COLOUR_H
+
+#include "aliases/aliases.h"
+#include <SDL_pixels.h>
+
+typedef struct {
+  union {
+    u32 abgr;
+    SDL_Color colour;
+  };
+} colour_t;
+
+#endif // !COLOUR_H